Peristaltic Pump

ABSTRACT

The peristaltic pump is provided with a two-piece housing ( 2, 3 ), in which a conveying member ( 1 ) as well as a pump tubing section ( 6 ) squeezable by the conveying member is received. For fixing the pump tubing section ( 6 ) in the housing ( 2, 3 ), a tubing holder ( 4 ) is provided. Further provided is a connecting element ( 5 ) provided with duct shaped connecting sockets ( 14   a,    14   b) for connecting tubing sections (   15   a,    15   b). For connecting the pump tubing section (   6 ) to the tubing holder ( 4 ), the two ends of the particular pump tubing section ( 6 ) are fixed in receptacles ( 10   a,    10   b) of the tubing holder (   4 ), which positively enclose the outside of the pump tubing section ( 6 ). The connecting element ( 5 ) is fixed to the tubing holder ( 4 ) by means of a snap-on connection. Thereby, the connecting sockets ( 14   a,    14   b) thereof are sealingly connected to the particular pump tubing section (   6 ).

BACKGROUND

The present invention relates to peristaltic pumps. Peristaltic pumps ofthe kind referred to herein are basically known. They are used forconveying different liquid and gaseous media.

The document DE 198 14 943 A1 discloses a flexible tube pump of the kindreferred to herein. The pump is provided with a pump housing in which isarranged the pump tubing as well as a rotor provided with two stranglingmeans in the shape of rollers. In order to connect the two ends of thepump tubing to the connecting pipes and connecting ports, respectively,flange members are provided that are fixed by means of threaded bolts.

One object of the present invention is to improve the design of aperistaltic pump in such a way that it can be manufactured at lower costand in a simpler manner, and that the pump tubing can be replacedquickly and easily, if required.

Due to the fact that the pump is provided with a tubing holder adaptedto be fixed to the housing, to which the end of the pump tubing is fixedand comprising at least one connecting element having connecting socketsfor fixing connecting tubes, whereby the connecting sockets aresealingly connected to the particular pump tubing upon fixing theconnecting element to the tubing holder, the pump tubing can beconnected to the tubing holder prior to assembling the pump. Thus, thetubing holder can be inserted, together with the pump tubing, into thetubing receptacle of the pump. In order to connect the pump tubing tothe connecting tubes, thereafter, only the connecting element has to befixed to the tubing holder. This is accomplished preferably by means ofa snap-on connection.

DESCRIPTION OF THE FIGURES

In the following, a preferred embodiment of the invention is furtherexplained by means of drawings. In these drawings,

FIG. 1 shows an exploded view of the peristaltic pump;

FIG. 2 shows a cross sectional view of a tubing holder, a connectingelement as well as a pump tube section;

FIG. 3 shows a cross sectional view of a tubing holder including thepump tube section connected thereto;

FIG. 4 shows a cross sectional view of the tubing holder, the connectingelement and the pump tube section in an assembled state;

FIG. 5 shows a longitudinal sectional view of the elements of FIG. 4;and

FIG. 6 shows a cross sectional view of an alternative embodiment of atubing holder as well as two connecting elements in an enlargedillustration.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 shows a six channel peristaltic pump in an exploded view. Sinceperistaltic pumps of the kind referred to herein are basically known, inthe following, the basic elements of the pump will be not addressed indetail, but only some of the components important in connection with thepresent invention. Essentially, the pump consists of a conveying member1, an upper housing portion 2, a lower housing portion 3, a tubingholder 4 as well as of a connecting element, generally designated byreference numeral 5 and comprising a first connecting element 5 a and asecond connecting element 5 b. Moreover, the pump comprises, in total,six pump tube sections, whereby only one pump tube section 6 is shownfor the sake of clarity.

The upper housing portion 2 is designed as a support frame member onwhich is supported, amongst others, the rotating conveying member 1. Thetop side of the upper housing portion 2 is provided with a support barmember 20. The lower housing portion 3 is connected to the upper housingportion be means of a snap-on connection and serves for receiving andpositively supporting the pump tubing. The conveying member 1 comprisesa shaft 7 driven by an electric motor (not shown) and is provided withthree axles 8 on which are rotatably received, in each case, severalconveying rollers.

As one important element of the invention, a tubing holder 4 is providedto fix the ends of six pump tube sections. To this end, the tubingholder 4 is provided with twelve receptacles 10 a, 10 b, preferablyprovided in two opposing rows. The inner sides of the receptacles are ofhollow cylindrical shape, but may be preferably of conical shape. Thetwo ends of a pump tube section can be fixed to each opposing pair ofthese receptacles 10 a, 10 b, the two ends of a pump tube section can befixed. Moreover, the tubing holder 4 is provided with four elasticallyresilient brackets 11 to which the two connecting elements 5 a, 5 b canbe fixed in the sense of a snap-on connection, as will be furtherexplained herein after. The upper portion 2 thereof is provided withfour latches 17 for fixing the tubing holder 4 to the housing. Moreover,evident from the drawing of FIG. 1 is a positioning element 19asymmetrically arranged on the upper portion 2 of the housing, adaptedto engage an opening (not shown) of the tubing holder 4 to ensure apositionally correct assembly of the tubing holder 4 and the upperportion 2 of the housing. The final position of the tubing holder 4 atthe upper portion 2 of the housing is determined by the latches 17 aswell as by stop members 12, the latter ones being provided onprotrusions of the upper portion 2 of the housing.

The two connecting elements 5 a, 5 b are provided, at their bottomsides, in each case with six tube-shaped extension members 13 a, 13 b,while their top sides are provided, in each case, with six tube-shapedconnecting sockets 14 a, 14 b. Each of the tube-shaped extension members13 a, 13 b is connected to the corresponding tube-shaped connectingsockets 14 a, 14 b via a continuous channel 18 a, 18 b. The tube-shapedextension members 13 a, 13 b located at the bottom side have a slightlyconical outside and constitute the male part of a plug-in connection forestablishing a sealed connection to the particular pump tube section,without the need to provide additional sealing elements. The connectingtubes to the pump are fixed to the tube-shaped connecting sockets 14 a,14 b located at the top side. Representative for the total of twelveconnecting tubes, only two tube sections 15 a, 15 b are shown in FIG. 1.The two connecting elements 5 a, 5 b are provided at both end faces withcatch members 16 a, 16 b by means of which they can be fixed to thebrackets 11 of the connecting element 5. Instead of two separateconnecting elements 5 a, 5 b, a common single connecting element couldbe provided, having two parallel rows of tube-shaped extension members13 a, 13 b and connecting sockets 14 a, 14 b.

The advantage of two separate connecting elements 5 a, 5 b, on the onehand, is that it can be attached quickly and simply to the top portion 2of the housing even if the support bar is present. Moreover, advantagesin manufacturing and costs are evident if two substantially equalelements can be manufactured instead of a single complicated element.The two connecting elements 5 a, 5 b are of the same design, except fora possible coding that prevents confusion and/or wrong assembly. Inorder to code the connecting elements 5 a, 5 b such that they cannot beconnected in a wrong way, the tubing holder 4 can be provided, forexample, with protrusions 24 and the connecting elements 5 a, 5 b withcorresponding recesses (not shown).

In the subsequent FIGS. 2 to 5, only the tubing holder 4, a single tubesection 6 and, if appropriate, the connecting element 5 are shown. Theillustration of further elements of the pump has been set aside. FIG. 2shows, in a detailed illustration, the tubing holder 4, the twoconnecting elements 5 a, 5 b and the pump tube section 6 in a crosssectional view. Besides the two brackets 11, the hollow cylindricalreceptacles 10 a, 10 b of the tubing holder 4 can be seen. Thereceptacles 10 a, 10 b are provided with a conical inserting portion 21a, 21 b, facilitating the insertion of the particular ends 6 a, 6 b ofthe pump tube sections 6. Although in the preferred embodiment thereceptacles are defined as hollow cylindrical, the inside need not beabsolutely cylindrical, but the inside diameter of the receptacles maypreferably slightly decrease towards the top. In any case, the innerdiameter of the particular receptacle 10 a, 10 b is matched to the outerdiameter of the pump tube section in such a way that the particular end6 a, 6 b of the pump tube section 6 is grasped in a positive fittingmanner, i.e., without any substantial gap. In a conical design of thereceptacle 10 a, 10 b, the particular end 6 a, 6 b of the pump tubesection 6 is slightly compressed towards its front face. By means of thedesign, i.e., the shape, of the receptacles 10 a, 10 b of the tubingholder 4, a positive or non-positive embracing of the pump tube sectioncan be assured. Preferably, the two ends of the tubing 6 a, 6 b arecemented to the particular receptacle 10 a, 10 b.

FIG. 3 shows the pump tube section 6 fixed to the tubing holder 4,whereby, for the sake of clarity, the illustration of the brackets hasbeen omitted. It is evident from this illustration that the two ends 6a, 6 b of the pump tube section 6 are flush with the front faces 22 a,22 b of the particular receptacle 10 a, 10 b. The two ends 6 a, 6 b ofthe pump tube section 4 are cemented to the receptacles 10 a, 10 b ofthe tubing holder 4 and, thus positively fixed thereto.

FIG. 4 shows a cross sectional view of the tubing holder 4, of theconnecting element 5 and of the pump tube section 6 in an assembledstate. Upon fixing the connecting element 5 to the tubing holder 4, thetube shaped extension members 13 a, 13 b of the connecting element 5penetrate the associated end 6 a, 6 b of the pump tube section 6 andestablish a sealed connection between the particular extension member 13a, 13 b and the pump tube section 6. Contributing to the sealedconnection are both the shape of the extension members 13 a, 13 b andthe shape of the receptacles 10 a, 10 b, as well as the fact that theend of the pump tube section 6 a, 6 b is positively grasped by theparticular receptacle 10 a, 10 b, such that the particular end of thepump tube section 6 a, 6 b cannot evade radially, but sealinglysurrounds the particular extension member 13 a, 13 b. The pump tubeitself and the two pump tube section ends 6 a, 6 b, respectively,constitute the sealing element of the transition, with the result thatadditional sealing elements like, for example, O-rings, are notnecessary. By abstaining from using additional sealing elements, thenumber of potentially leaking elements can be reduced to an absoluteminimum. Due to the fact that the extension members 13 a, 13 b have asmooth outside, i.e., are not designed barb-like, the push-on connectionbetween tubing holder 4 and connecting element 5 can be easily releasedmanually and re-established in a sealing manner, whereby this operationcan be repeated several times, if appropriate.

From FIG. 5, showing a longitudinal sectional view of the elements ofFIG. 4, namely the tubing holder 4, the connecting element 5 and thepump tube section 6, it is particularly evident how the brackets 11 ofthe tubing holder 4 fix the connecting element 5 to the catch members 16a, 16 b. Further visible from this illustration are protrusions 24arranged on the connecting element 5, engaging corresponding recesses 25of the tubing holder 4 to correctly position the connecting element 5with regard to the tubing holder 4 and, thereby, also with regard to thehousing of the pump.

FIG. 6 shows a cross sectional view of an alternative embodiment of atubing holder 27 as well as of two connecting elements 28 a, 28 b in alarger scale. One difference, as compared to the foregoing embodiment,is that the protrusion 29 a, 29 b of the connecting elements 28 a, 28 b,facing the pump tube section 34, are provided with barb-like shoulders30 a, 30 b at the outside. These barb-like shoulders 30 a, 30 b improvethe reliability of the connection between the pump tube section 34 andthe assigned protrusion 29 a, 29 b, which is particularly advantageousif a pulling force is exerted to the connection or if there is a highinternal pressure. The receptacles 31 a, 31 b of the tubing holder 27each are provided with a cylindrical recess 32 a, 32 b, enabling aradial enlargement of the ends of the pump tube sections when they arepushed, during assembling, over the barb-like shoulders. The innerdiameter of the two receptacles 31 a, 31 b in the region of theparticular cylindrical recess 32 a, 32 b is sufficiently tight that, onthe one hand, the barb-like shoulders 30 a, 30 b can penetrate theassigned end of the pump tube section without great resistance. On theother hand, the inner diameter must be sufficient so that thereceptacles 31 a, 31 b radially enclose the assigned end of the pumptube section if this end starts to enlarge in the region of thebarb-like shoulders 30 a, 30 b under the influence of hydrostatic innerpressure. In other words, the radial gap between the receptacles 31 a,31 b and the assigned end of the pump tube section is chosen such thatthe barb-like shoulders can relatively easily penetrate the end of thetube, while the other side the receptacles 31 a, 31 b counteract to aradial enlargement of the end of the tube in the case of higher internalpressure to reduce the risk of leakage.

The lower side of the particular receptacle 31 a, 31 b facing theinterior of the pump is provided with a facet 33 a, 33 b, ending in acylindrical or conical inserting portion. The facets 33 a, 33 b aremeant to facilitate the introduction of the assigned end portion of thetube into the receptacle 31 a, 31 b, while the inserting portionadditionally favors the penetration of adhesive material upon cementingthe pump tube section and the end of the tube, respectively, to theassigned receptacle 31 a, 31 b.

The advantages of the pump described herein may be seen particularly inthe fact that the pump tube sections can be pre-assembled remote fromthe pump itself, i.e., connected to the tubing holder. Such assemblystep can be performed extensively automatedly and ensures advantages asfar as assembly costs, precision and durability are concerned. Once thepump is assembled, only the two connecting elements provided with thepump tube sections have to be locked into place at the tubing holder inorder to ensure that the pump is hydraulically ready for operation. Sucha pump can be assembled, essentially without using any tools and with afew manual operations. If the outside of the receptacles 13 a, 13 b isessentially smooth and does not have barb-like shoulders, the pump tubesections, if needed, can be replaced very quickly and easily byreplacing the connecting element 4 with the pump tube sections 6cemented thereto as an unit. The aforementioned advantages are presentboth in one channel pumps and particularly in multi-channel pumps.

1-13. (canceled)
 14. Peristaltic pump, having a conveying member (1)received in a housing (2, 3), and having at least one flexible pump tubesection (6) being squeezable by said conveying member (1) forperistalticly conveying a medium, said pump comprising a tubing holder(4) adapted to be attached to the housing (2) to which the pump tubesection (6) is attached, said tubing holder (4) having at least oneconnecting element (5) for connecting tubing sections (15 a, 15 b) forfluid communication with the pump tube section (6), said at least oneconnecting element (5) including connecting sockets (14 a, 14 b)configured for sealing connection with the pump tube section (6) uponconnecting the connecting element (5) to the pump tube section (6). 15.The peristaltic pump according to claim 14, wherein said tubing holder(4) is provided with hollow cylindrical or conical receptacles (10 a, 10b), to which corresponding end portions (6 a, 6 b) of the pump tubingsection (6) are connected and positively and/or non-positively enclosed.16. The peristaltic pump according to claim 15, wherein said connectingelement (5) is provided with duct shaped extension members (13 a, 13 b)that are configured to penetrate said corresponding end portions (6 a, 6b) of the pump tubing section (6) and are further configured to radiallyload said end portions upon connecting the connecting element (5) to thetubing holder (4).
 17. The peristaltic pump according to claim 16,wherein said connecting element (5) is provided with connecting sockets(14 a, 14 b) for connecting tubing sections (15 a, 15 b) and withextension members (13 a, 13 b) for sealingly connecting the pump tubingsection (6), whereby each of said connecting sockets (14 a, 14 b)communicates with a corresponding extension member (13 a, 13 b) througha corresponding continuous channel (18 a, 18 b).
 18. The peristalticpump according to claim 16, wherein said duct-shaped extension members(29 a, 29 b) are provided with a smooth outside surface.
 19. Theperistaltic pump according to claim 16, wherein said duct-shapedextensions (29 a, 29 b) are provided with barb-like shoulders (30 a, 30b).
 20. The peristaltic pump according to claim 14, wherein said tubingholder (4) is attachable to the housing (2) by means of a quick-releaseconnection.
 21. The peristaltic pump according to claim 20, wherein saidquick-release connection includes a latch or snap-on connection.
 22. Theperistaltic pump according to claim 14, wherein said connecting element(5) is attachable to the tubing holder (4) by means of a quick releaseconnection.
 23. The peristaltic pump according to claim 22, wherein saidquick-release connection is a latch or snap-on connection.
 24. Theperistaltic pump according to claim 14, wherein said end portion (6 a, 6b) of the particular pump tubing section (6) is cemented to thereceptacle (10 a, 10 b).
 25. The peristaltic pump according to claim 14,wherein positioning elements (24, 25) are provided between saidconnecting element (5) and said tubing holder (4) for positioning saidconnecting element (5) relative to said tubing holder (4).
 26. Theperistaltic pump according to claim 14, wherein the housing (2) isprovided with at least one positioning element (19) to ensure a correctpositional arrangement of the tubing holder (4) on the housing (2). 27.The peristaltic pump according to claim 14, wherein said tubing holder(4) is provided with two parallel rows of receptacles (10 a, 10 b) forfixing several two or more pump tube sections, and further wherein twoconnecting elements (5 a, 5 b) are provided, a corresponding one ofwhich is attachable to one of the parallel rows of receptacles (10 a, 10b).
 28. The peristaltic pump according to claim 27, wherein said twoconnecting elements (5 a, 5 b) are of substantially identicalconfiguration.
 29. The peristaltic pump according to claim 27, whereinsaid connecting elements (5 a, 5 b) are of different construction, andfurther wherein positioning elements are provided between the housingand a corresponding one of said connecting elements (5 a, 5 b), saidpositioning elements configured to ensure a correct positionalarrangement of the particular connecting element (5 a, 5 b) with regardto the housing (2).